From: Antoni Boucher <bouanto@zoho.com>
To: David Malcolm <dmalcolm@redhat.com>
Cc: jit@gcc.gnu.org,
Antoni Boucher via Gcc-patches <gcc-patches@gcc.gnu.org>
Subject: Re: [PATCH] libgccjit: Handle truncation and extension for casts [PR 95498]
Date: Fri, 18 Jun 2021 17:11:58 -0400 [thread overview]
Message-ID: <bd1e9dd2b5ab82b372905fa99cb91b06609483b5.camel@zoho.com> (raw)
In-Reply-To: <bcf5681fb1698510e5477289c8da1b61fb14bb0a.camel@redhat.com>
[-- Attachment #1: Type: text/plain, Size: 11922 bytes --]
Ok.
Here's the patch with the updated subject and with format fixed.
Le vendredi 18 juin 2021 à 16:54 -0400, David Malcolm a écrit :
> On Fri, 2021-06-18 at 16:42 -0400, Antoni Boucher wrote:
> > I'm sending the patch once again for review.
> >
> > As it's the first time I'll land a patch, I'm not sure what needs
> > to be
> > done when it's approved.
> > Do I just commit it to the master branch directly?
>
> Commit (and push), yes, but...
>
> Please ensure the subject line of the commit matches our policy:
>
> "libgccjit: Handle truncation and extension for casts [PR95498]"
>
> is a good subject, whereas:
>
> "This patch handles truncation and extension for casts in jit."
>
> is not.
>
> We have some hooks that will only accept pushes if the commit message
> has a correctly formatted ChangeLog. The hooks ought to also add
> notification comments to bugzilla for any bugs mentioned in the
> commit
> message.
>
> See https://gcc.gnu.org/gitwrite.html#checkin
>
>
> FWIW in my own workflow I have a writable working copy that I keep
> for
> just doing pushes;
> I do a
> git pull
> verify the build, then
> git am FOO.patch --ignore-date
> to apply the patch that was tested and approved, then do a last test
> with that, then
> git push
>
> That way I only push the patches that I've tested and have been
> approved, and the other ones are in an entirely separate working
> copy.
> This may be overkill though.
>
> I'm also on #gcc IRC right now on OFTC (dmalcolm) if you run into
> issues.
>
> Dave
>
> >
> > Thanks!
> >
> > Le vendredi 11 juin 2021 à 13:49 -0400, David Malcolm a écrit :
> > > On Thu, 2021-05-27 at 21:22 -0400, Antoni Boucher wrote:
> > > > Here's the patch with the condition removed.
> > > > I believe everything is now fixed.
> > > > Thanks!
> > >
> > > Thanks; this looks good to me. Is this the latest version of the
> > > patch; would you like me to apply it?
> > >
> > > Dave
> > >
> > > >
> > > > Le jeudi 27 mai 2021 à 18:21 -0400, David Malcolm a écrit :
> > > > > On Tue, 2021-05-25 at 20:16 -0400, Antoni Boucher wrote:
> > > > > > I updated the patch according to the comments by Tom
> > > > > > Tromey.
> > > > > >
> > > > > > There's one question left about your question regarding
> > > > > > C_MAYBE_CONST_EXPR, David:
> > > > > >
> > > > > > I am not sure if we can get a C_MAYBE_CONST_EXPR from
> > > > > > libgccjit,
> > > > > > and
> > > > > > it
> > > > > > indeed seems like it's only created in c-family.
> > > > > > However, we do use it in libgccjit here:
> > > > > > https://github.com/gcc-mirror/gcc/blob/master/gcc/jit/jit-playback.c#L1180
> > > > > >
> > > > > > I tried removing the condition `if (TREE_CODE (t_ret) !=
> > > > > > C_MAYBE_CONST_EXPR)` and all the tests of libgccjit still
> > > > > > pass.
> > > > > >
> > > > > > That code was copied from here:
> > > > > > https://github.com/gcc-mirror/gcc/blob/master/gcc/c/c-convert.c#L175
> > > > > > and might not be needed in libgccjit.
> > > > > >
> > > > > > Should I just remove the condition, then?
> > > > >
> > > > > I think so.
> > > > >
> > > > > Thanks
> > > > > Dave
> > > > >
> > > > > >
> > > > > > Le jeudi 13 mai 2021 à 19:58 -0400, David Malcolm a écrit :
> > > > > > > On Thu, 2021-05-13 at 19:31 -0400, Antoni Boucher wrote:
> > > > > > > > Thanks for your answer.
> > > > > > > >
> > > > > > > > See my answers below:
> > > > > > > >
> > > > > > > > Le jeudi 13 mai 2021 à 18:13 -0400, David Malcolm a
> > > > > > > > écrit :
> > > > > > > > > On Sat, 2021-02-20 at 17:17 -0500, Antoni Boucher via
> > > > > > > > > Gcc-
> > > > > > > > > patches
> > > > > > > > > wrote:
> > > > > > > > > > Hi.
> > > > > > > > > > Thanks for your feedback!
> > > > > > > > > >
> > > > > > > > >
> > > > > > > > > Sorry about the delay in responding.
> > > > > > > > >
> > > > > > > > > In the past I was hesitant about adding more cast
> > > > > > > > > support
> > > > > > > > > to
> > > > > > > > > libgccjit
> > > > > > > > > since I felt that the user could always just create a
> > > > > > > > > union
> > > > > > > > > to
> > > > > > > > > do
> > > > > > > > > the
> > > > > > > > > cast. Then I tried actually using the libgccjit API
> > > > > > > > > to
> > > > > > > > > do
> > > > > > > > > this,
> > > > > > > > > and
> > > > > > > > > realized how much work it adds, so I now think we do
> > > > > > > > > want
> > > > > > > > > to
> > > > > > > > > support
> > > > > > > > > casting more types.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > See answers below:
> > > > > > > > > >
> > > > > > > > > > On Sat, Feb 20, 2021 at 11:20:35AM -0700, Tom
> > > > > > > > > > Tromey
> > > > > > > > > > wrote:
> > > > > > > > > > > > > > > > "Antoni" == Antoni Boucher via Gcc-
> > > > > > > > > > > > > > > > patches
> > > > > > > > > > > > > > > > <
> > > > > > > > > > > > > > > > gcc-patches@gcc.gnu.org> writes:
> > > > > > > > > > >
> > > > > > > > > > > Antoni> gcc/jit/
> > > > > > > > > > > Antoni> PR target/95498
> > > > > > > > > > > Antoni> * jit-playback.c: Add support to
> > > > > > > > > > > handle
> > > > > > > > > > > truncation
> > > > > > > > > > > and extension
> > > > > > > > > > > Antoni> in the convert function.
> > > > > > > > > > >
> > > > > > > > > > > Antoni> + switch (dst_code)
> > > > > > > > > > > Antoni> + {
> > > > > > > > > > > Antoni> + case INTEGER_TYPE:
> > > > > > > > > > > Antoni> + case ENUMERAL_TYPE:
> > > > > > > > > > > Antoni> + t_ret = convert_to_integer
> > > > > > > > > > > (dst_type,
> > > > > > > > > > > expr);
> > > > > > > > > > > Antoni> + goto maybe_fold;
> > > > > > > > > > > Antoni> +
> > > > > > > > > > > Antoni> + default:
> > > > > > > > > > > Antoni> + gcc_assert
> > > > > > > > > > > (gcc::jit::active_playback_ctxt);
> > > > > > > > > > > Antoni> + gcc::jit::active_playback_ctxt-
> > > > > > > > > > > > add_error
> > > > > > > > > > > (NULL,
> > > > > > > > > > > "unhandled conversion");
> > > > > > > > > > > Antoni> + fprintf (stderr, "input
> > > > > > > > > > > expression:\n");
> > > > > > > > > > > Antoni> + debug_tree (expr);
> > > > > > > > > > > Antoni> + fprintf (stderr, "requested
> > > > > > > > > > > type:\n");
> > > > > > > > > > > Antoni> + debug_tree (dst_type);
> > > > > > > > > > > Antoni> + return error_mark_node;
> > > > > > > > > > > Antoni> +
> > > > > > > > > > > Antoni> + maybe_fold:
> > > > > > > > > > > Antoni> + if (TREE_CODE (t_ret) !=
> > > > > > > > > > > C_MAYBE_CONST_EXPR)
> > > > > > > > >
> > > > > > > > > Do we even get C_MAYBE_CONST_EXPR in libgccjit? That
> > > > > > > > > tree
> > > > > > > > > code
> > > > > > > > > is
> > > > > > > > > defined in c-family/c-common.def; how can nodes of
> > > > > > > > > that
> > > > > > > > > kind
> > > > > > > > > be
> > > > > > > > > created
> > > > > > > > > outside of the c-family?
> > > > > > > >
> > > > > > > > I am not sure, but that seems like it's only created in
> > > > > > > > c-
> > > > > > > > family
> > > > > > > > indeed.
> > > > > > > > However, we do use it in libgccjit here:
> > > > > > > >
> > > > > > > > https://github.com/gcc-mirror/gcc/blob/master/gcc/jit/jit-playback.c#L1180
> > > > > > > >
> > > > > > > > >
> > > > > > > > > > > Antoni> + t_ret = fold (t_ret);
> > > > > > > > > > > Antoni> + return t_ret;
> > > > > > > > > > >
> > > > > > > > > > > It seems weird to have a single 'goto' to
> > > > > > > > > > > maybe_fold,
> > > > > > > > > > > especially
> > > > > > > > > > > inside
> > > > > > > > > > > a switch like this.
> > > > > > > > > > >
> > > > > > > > > > > If you think the maybe_fold code won't be reused,
> > > > > > > > > > > then
> > > > > > > > > > > it
> > > > > > > > > > > should
> > > > > > > > > > > just
> > > > > > > > > > > be
> > > > > > > > > > > hoisted up and the 'goto' removed.
> > > > > > > > > >
> > > > > > > > > > This actually depends on how the support for cast
> > > > > > > > > > between
> > > > > > > > > > integers
> > > > > > > > > > and
> > > > > > > > > > pointers will be implemented (see below).
> > > > > > > > > > If we will support truncating pointers (does that
> > > > > > > > > > even
> > > > > > > > > > make
> > > > > > > > > > sense?
> > > > > > > > > > and
> > > > > > > > > > I
> > > > > > > > > > guess we cannot extend a pointer unless we add the
> > > > > > > > > > support
> > > > > > > > > > for
> > > > > > > > > > uint128_t), that label will be reused for that
> > > > > > > > > > case.
> > > > > > > > > > Otherwise, it might not be reused.
> > > > > > > > > >
> > > > > > > > > > So, please tell me which option to choose and I'll
> > > > > > > > > > update
> > > > > > > > > > my
> > > > > > > > > > patch.
> > > > > > > > >
> > > > > > > > > FWIW I don't think we'll want to support truncating
> > > > > > > > > or
> > > > > > > > > extending
> > > > > > > > > pointers.
> > > > > > > >
> > > > > > > > Ok, but do you think we'll want to support casts
> > > > > > > > between
> > > > > > > > integers
> > > > > > > > and
> > > > > > > > pointers?
> > > > > > >
> > > > > > > Yes, though we probably want to reject truncating a
> > > > > > > pointer
> > > > > > > into
> > > > > > > a
> > > > > > > smaller integer type.
> > > > > > >
> > > > > > > > I opened an issue about this
> > > > > > > > (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95438)
> > > > > > > > and
> > > > > > > > would
> > > > > > > > be
> > > > > > > > willing to do a patch for it eventually.
> > > > > > > >
> > > > > > > > > >
> > > > > > > > > > > On the other hand, if the maybe_fold code might
> > > > > > > > > > > be
> > > > > > > > > > > reused
> > > > > > > > > > > for
> > > > > > > > > > > some
> > > > > > > > > > > other
> > > > > > > > > > > case, then I suppose I would have the case end
> > > > > > > > > > > with
> > > > > > > > > > > 'break'
> > > > > > > > > > > and
> > > > > > > > > > > then
> > > > > > > > > > > have this code outside the switch.
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > In another message, you wrote:
> > > > > > > > > > >
> > > > > > > > > > > Antoni> For your question, the current code
> > > > > > > > > > > already
> > > > > > > > > > > works
> > > > > > > > > > > with
> > > > > > > > > > > boolean and
> > > > > > > > > > > Antoni> reals and casts between integers and
> > > > > > > > > > > pointers
> > > > > > > > > > > is
> > > > > > > > > > > currently
> > > > > > > > > > > not
> > > > > > > > > > > Antoni> supported.
> > > > > > > > > > >
> > > > > > > > > > > I am curious why this wasn't supported. It seems
> > > > > > > > > > > like
> > > > > > > > > > > something
> > > > > > > > > > > that
> > > > > > > > > > > one might want to do.
> > > > > > > > > >
> > > > > > > > > > I have no idea as this is my first contribution to
> > > > > > > > > > gcc.
> > > > > > > > > > But this would be indeed very useful and I opened
> > > > > > > > > > an
> > > > > > > > > > issue
> > > > > > > > > > about
> > > > > > > > > > this:
> > > > > > > > > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95438
> > > > > > > > > >
> > > > > > > > > > > thanks,
> > > > > > > > > > > Tom
> > > > > > > > > >
> > > > > > > > > > Thanks!
> > > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > >
> > >
> > >
> >
>
>
[-- Attachment #2: 0001-libgccjit-Handle-truncation-and-extension-for-casts-.patch --]
[-- Type: text/x-patch, Size: 5262 bytes --]
From c6235c35364886e95376702240ad217106969b58 Mon Sep 17 00:00:00 2001
From: Antoni Boucher <bouanto@zoho.com>
Date: Sun, 5 Jul 2020 19:07:30 -0400
Subject: [PATCH] libgccjit: Handle truncation and extension for casts
[PR95498]
2020-07-12 Antoni Boucher <bouanto@zoho.com>
gcc/jit/
PR target/95498
* jit-playback.c (convert): Add support to handle truncation and
extension in the convert function.
gcc/testsuite/
PR target/95498
* jit.dg/all-non-failing-tests.h: New test.
* jit.dg/test-cast.c: New test.
Signed-off-by: Antoni Boucher <bouanto@zoho.com>
---
gcc/jit/jit-playback.c | 33 ++++++----
gcc/testsuite/jit.dg/all-non-failing-tests.h | 10 +++
gcc/testsuite/jit.dg/test-cast.c | 66 ++++++++++++++++++++
3 files changed, 98 insertions(+), 11 deletions(-)
create mode 100644 gcc/testsuite/jit.dg/test-cast.c
diff --git a/gcc/jit/jit-playback.c b/gcc/jit/jit-playback.c
index c6136301243..d26f08bfc1b 100644
--- a/gcc/jit/jit-playback.c
+++ b/gcc/jit/jit-playback.c
@@ -62,22 +62,33 @@ along with GCC; see the file COPYING3. If not see
/* gcc::jit::playback::context::build_cast uses the convert.h API,
which in turn requires the frontend to provide a "convert"
- function, apparently as a fallback.
-
- Hence we provide this dummy one, with the requirement that any casts
- are handled before reaching this. */
+ function, apparently as a fallback for casts that can be simplified
+ (truncation, extension). */
extern tree convert (tree type, tree expr);
tree
convert (tree dst_type, tree expr)
{
- gcc_assert (gcc::jit::active_playback_ctxt);
- gcc::jit::active_playback_ctxt->add_error (NULL, "unhandled conversion");
- fprintf (stderr, "input expression:\n");
- debug_tree (expr);
- fprintf (stderr, "requested type:\n");
- debug_tree (dst_type);
- return error_mark_node;
+ tree t_ret = NULL;
+ t_ret = targetm.convert_to_type (dst_type, expr);
+ if (t_ret)
+ return t_ret;
+ enum tree_code dst_code = TREE_CODE (dst_type);
+ switch (dst_code)
+ {
+ case INTEGER_TYPE:
+ case ENUMERAL_TYPE:
+ return fold (convert_to_integer (dst_type, expr));
+
+ default:
+ gcc_assert (gcc::jit::active_playback_ctxt);
+ gcc::jit::active_playback_ctxt->add_error (NULL, "unhandled conversion");
+ fprintf (stderr, "input expression:\n");
+ debug_tree (expr);
+ fprintf (stderr, "requested type:\n");
+ debug_tree (dst_type);
+ return error_mark_node;
+ }
}
namespace gcc {
diff --git a/gcc/testsuite/jit.dg/all-non-failing-tests.h b/gcc/testsuite/jit.dg/all-non-failing-tests.h
index 4202eb7798b..84ef54a0386 100644
--- a/gcc/testsuite/jit.dg/all-non-failing-tests.h
+++ b/gcc/testsuite/jit.dg/all-non-failing-tests.h
@@ -98,6 +98,13 @@
#undef create_code
#undef verify_code
+/* test-cast.c */
+#define create_code create_code_cast
+#define verify_code verify_code_cast
+#include "test-cast.c"
+#undef create_code
+#undef verify_code
+
/* test-compound-assignment.c */
#define create_code create_code_compound_assignment
#define verify_code verify_code_compound_assignment
@@ -361,6 +368,9 @@ const struct testcase testcases[] = {
{"calling_internal_function",
create_code_calling_internal_function,
verify_code_calling_internal_function},
+ {"cast",
+ create_code_cast,
+ verify_code_cast},
{"compound_assignment",
create_code_compound_assignment,
verify_code_compound_assignment},
diff --git a/gcc/testsuite/jit.dg/test-cast.c b/gcc/testsuite/jit.dg/test-cast.c
new file mode 100644
index 00000000000..2b1e385ae40
--- /dev/null
+++ b/gcc/testsuite/jit.dg/test-cast.c
@@ -0,0 +1,66 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "libgccjit.h"
+
+#include "harness.h"
+
+void
+create_code (gcc_jit_context *ctxt, void *user_data)
+{
+ /* Let's try to inject the equivalent of:
+char
+my_casts (int x)
+{
+ return (char)(long) x;
+}
+ */
+ gcc_jit_type *int_type =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_INT);
+ gcc_jit_type *long_type =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_LONG);
+ gcc_jit_type *return_type =
+ gcc_jit_context_get_type (ctxt, GCC_JIT_TYPE_CHAR);
+
+ gcc_jit_param *x =
+ gcc_jit_context_new_param (
+ ctxt,
+ NULL,
+ int_type, "x");
+ gcc_jit_param *params[1] = {x};
+ gcc_jit_function *func =
+ gcc_jit_context_new_function (ctxt,
+ NULL,
+ GCC_JIT_FUNCTION_EXPORTED,
+ return_type,
+ "my_casts",
+ 1, params, 0);
+
+ gcc_jit_block *initial =
+ gcc_jit_function_new_block (func, "initial");
+
+ gcc_jit_block_end_with_return(initial, NULL,
+ gcc_jit_context_new_cast(ctxt,
+ NULL,
+ gcc_jit_context_new_cast(ctxt,
+ NULL,
+ gcc_jit_param_as_rvalue(x),
+ long_type
+ ),
+ return_type
+ ));
+}
+
+void
+verify_code (gcc_jit_context *ctxt, gcc_jit_result *result)
+{
+ typedef int (*my_casts_fn_type) (int);
+ CHECK_NON_NULL (result);
+ my_casts_fn_type my_casts =
+ (my_casts_fn_type)gcc_jit_result_get_code (result, "my_casts");
+ CHECK_NON_NULL (my_casts);
+ char val = my_casts (10);
+ note ("my_casts returned: %d", val);
+ CHECK_VALUE (val, 10);
+}
--
2.32.0
next prev parent reply other threads:[~2021-06-18 21:12 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-13 0:30 Antoni Boucher
2020-07-14 21:15 ` David Malcolm
2020-07-21 21:29 ` Andrea Corallo
2020-10-15 19:00 ` Antoni Boucher
2021-02-13 1:35 ` Antoni Boucher
2021-02-20 18:20 ` Tom Tromey
2021-02-20 22:17 ` Antoni Boucher
2021-05-13 8:34 ` Martin Liška
2021-05-13 22:13 ` David Malcolm
2021-05-13 23:31 ` Antoni Boucher
2021-05-13 23:58 ` David Malcolm
2021-05-26 0:16 ` Antoni Boucher
2021-05-27 22:21 ` David Malcolm
2021-05-28 1:22 ` Antoni Boucher
2021-06-11 17:49 ` David Malcolm
2021-06-18 20:42 ` Antoni Boucher
2021-06-18 20:54 ` David Malcolm
2021-06-18 21:11 ` Antoni Boucher [this message]
2021-06-19 9:08 ` Bernhard Reutner-Fischer
2021-07-06 13:00 ` Antoni Boucher
2021-07-08 20:44 ` David Malcolm
2021-07-08 21:28 ` Antoni Boucher
2021-07-08 21:34 ` David Malcolm
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